Missing Perl Modules?

I'm attempting to install XFCE from the file "xfce4-4.4RC2-installer.run", I execute this file and I'm presented with a nice intuitive GUI, which tells me I need certain Perl modules to make this work: URI:Escape, URI:file and URI:URL. It suggests to "Install from CPAN" with a button, I tried this -- which fails.Next I downloaded the file "http://search.cpan.org/CPAN/authors/id/ … .35.tar.gz" from CPAN manually, extracted this and installed the files into "/usr/lib/perl5/5.8.8/URI/", this solved the missing "URI:Escape", but none of the others, despite the other required files "file.pm" and "URL.pm" existing in the same directory. I also tried to copy all files to "/usr/lib/perl5/5.8.8/" as I'm not sure exactly where the XFCE-installer is looking, I also attempted to put them into "/usr/lib/perl5/5.8.4" and "/usr/lib/perl5/5.8.8/URI/". Next I tried to change extensions from .pm to .pl on the files in question.

I have read through the documentation in search for any help, I've also searched the forum. Could anyone give specific help on this issue?